US Bridges

Lemhi Road over Lemhi River (allen Br)

Good

Lemhi County, Idaho · 0.3 S. 0.8 E. Salmon · Structure no. 000000000032696

Built
2016
9 years old
Condition
Good
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
74 ft
1 main span
Daily traffic
880
2023 count
Owner
County
County Highway Agency

About this bridge

Lemhi Road over Lemhi River (allen Br) is a prestressed concrete stringer/multi-beam or girder carrying Lemhi Road over Lemhi River (allen Br) in Lemhi County, Idaho. It was built in 2016, so it is 9 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 880 vehicles a day, roughly 7% of them trucks, projected to reach 1,320 by 2042. The structure is 74 ft (22.6 m) long and 34 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesLemhi Road
CrossesLemhi River (allen Br)
Location0.3 S. 0.8 E. Salmon
RouteCounty Highway 0
CountyLemhi County
StateIdaho
Coordinates45.17267, -113.87742
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating64.6 US tons
Inventory rating49.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length74 ft (22.6 m)
Longest span70 ft (21.3 m)
Deck width34 ft (10.3 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic880 (2023)
Projected traffic1,320 by 2042
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Lemhi Road over Lemhi River (allen Br) built?

It was built in 2016, making it 9 years old in 2025.

What condition is Lemhi Road over Lemhi River (allen Br) in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2024.

How much traffic does Lemhi Road over Lemhi River (allen Br) carry?

About 880 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Lemhi Road over Lemhi River (allen Br)?

The structure is 74 ft (22.6 m) long with a longest span of 70 ft (21.3 m) and a deck 34 ft wide.

Who owns Lemhi Road over Lemhi River (allen Br)?

It is owned by the County Highway Agency.